In a surprising move arranged by prosecutors in Los Angeles and Washington, the authorities in Switzerland arrested the film director Roman Polanski late Saturday as he arrived at the Zurich airport, paving the way for his possible extradition to the United States in connection with a 32-year-old sex case.

Mr. Polanski, 76, a French citizen, was detained as he arrived to receive an award at the Zurich Film Festival. Although he is expected to oppose extradition, the arrest raised a strong possibility that Mr. Polanski would be returned to the United States to face sentencing under his conviction for having had sex with a 13-year-old girl in 1977.

The article also touches on the recent documentary film Roman Polanski: Wanted and Desired, which was released in late 2008 and focused on claims of judicial and prosecutorial wrongdoing at the time of Polanski's arrest.